The present invention relates to a device for pretreating plastic waste before recycling and, more particularly, to a device for separating, from plastic waste, other substances or matters which the waste may be mixed with and for delivering this waste washed and dried.
Much plastic waste of industrial, agricultural or domestic origin is often mixed with other solid materials, dirtied by contacting other various substances or else covered with depositions, and coatings to be recovered or at least partly removed.
This is the case for numerous plastic objects or films which have been used for conditioning, packaging or protecting of products, that is, films, polyethylene or PVC vessels. It is, for example, also the case for photofilms or X-ray plates the sensitive depositions which are to be recycled. It is also the case, for example, with films covered or coated with other substances that are to be at least partially removed before their treatment.
The possible reuse of this waste or its recycling first requires a pretreatment comprising a crushing or severance and a total or partial separation of the foreign products or substances through washing and drying, in order to obtain recyclable waste.
Devices capable of treating plastic waste are described in published European patent applications 94,282 or 310,947 as well as in published French patent applications 2,573,340 or 2,599,279.
Treating plastic waste is often achieved in extensive plants including numerous functional subsets which must be installed in a permanent manner, which often implies a centralization of the waste to be treated, and which requires a trained operator. The cost and the cost-in-use of such plants are generally very high. These types of plants, in view of size and of operating costs, are not suitable for many applications.
Very often, the problem to be solved for the treatment of plastic waste consists in obtaining a reliable device that can reach a high treatment rate and which is economically profitable; works with an amount of washing liquid with a low renewal rate in order to avoid pollution problems or to facilitate the possible recovery of certain substances separated by the washing; is sufficiently compact to be able to be easily transported to waste accumulation spots; and is equipped with controls that are sufficiently elaborated to enable operation without difficulty and to be used, preferably, by a non-specialized operator.